An assisted guidance and navigation method in intraoral surgeries is a method using computerized tomography (CT) photography and an optical positioning system to track medical appliances, the method including: first providing an optical positioning treatment instrument and an optical positioning device then obtaining image data of the intraoral tissue receiving treatment through CT photography, precisely displaying actions of the treatment instrument in the image data, and real-time checking an image and guidance and navigation. Therefore, during the surgery, the existing use habits of the physicians are not affected and accurate and convenient auxiliary information is provided, and attention is paid to using the treatment instrument in physical environments such as a patients tooth or dental model.